Fibre reinforcement is commonly used in a wide variety of rubber goods, including tires, geotextile membranes, hoses and belts. It is critical to ensure good adhesion between the fibre and rubber in such goods, so that the fibre/rubber interface is not the primary cause of failure. This need is particularly acute for dynamic applications, such as belts, where the flexing of the rubber product increases the stress on the rubber-to-fibre bond.
Hydrogenated nitrile rubber, also referred to herein as HNBR, is employed in the production of fibre-reinforced belts (e.g. timing belts, conveyor belts, v-belts). HNBR has a balance of strength, heat resistance and oil resistance properties which suggests its use in belts that are used in harsh environments. Examples of reinforced belts made from hydrogenated nitrile rubber are disclosed in U.S. Pat. Nos. 4,643,938, 4,762,745 and 4,721,496. However, the adhesion characteristics of HNBR to conventional reinforcing fibres are mediocre. Accordingly, there is a need to provide improved adhesion between HNBR and reinforcing fibres, particularly for use in fibre-reinforced belts.